CHICAGO — New guidelines aimed at preventing workplace discrimination against pregnant women were signed into law this week by Gov. Pat Quinn, a move backers say extends protections already in place for other workers.

House Bill 8 was prompted by safety and health concerns for expectant mothers and their children, said sponsors Rep. Mary Flowers and Sen. Toi Hutchinson, both Democrats. Quinn’s office cited a U.S. Equal Employment Opportunity study showing a major increase — more than 70 percent — in the number of pregnancy discrimination claims from 1992 to 2011.

“No pregnant woman should have to choose between having her baby and keeping her job,” Quinn said today at a Chicago clinic during an event marking the signing. “That’s really what this law is all about.”

He signed the legislation late Monday, aides said.

The law, which takes effect in January, extends workplace protections to pregnant women, including requiring employers to consider accommodations if asked. That includes limits on manual labor, time for more frequent bathroom breaks and space to breast-feed.

The law also says a pregnant woman can’t be forced to take a leave of absence when another workplace accommodation is available, and an employer can’t refuse to hire a qualified applicant because of a required accommodation. The law outlines how complaints can be filed if an employee feels an employer isn’t complying.

During debate on the bill this year, opponents said they feared that the plan would prompt a rise in lawsuits and could hurt small businesses.

But proponents, who called it a “pro-family law,” said it’s the same situation as an employee who has an injury affecting their work and asks for modified duties, such as being able to sit down or take breaks to rest.